32results about How to "Spectrum adjustable" patented technology

The invention relates to a distributed optical fiber positioning system, in particular to an OTDR (Optical Time Domain Reflectometer) device and a measurement method based on physical random code correlation detection, and solves the contradiction that the dynamic range and the spatial resolution of a traditional OTDR system cannot be improved at the same time. The device comprises a physical random code generator, a microwave amplifier, a DFB laser, an electro-optical phase modulator, an optical isolator, a first optical amplifier, a 1 * 2 optical fiber coupler, a variable optical delay line,a first photoelectric detector, an oscilloscope, a to-be-detected optical fiber, an optical circulator, a second optical amplifier, a second photoelectric detector and a computer. The system is simple in structure, convenient to operate and low in cost, the spatial resolution is determined by the code width of the physical random code, the problem that the spatial resolution is deteriorated due to the weak period of a chaotic laser signal is avoided, and adjustment of high spatial resolution acquisition is also very convenient.

The invention discloses a direct-phase-modulation-based femtosecond wideband pulse generation optical ring in the technical field of wireless communication. The direct-phase-modulation-based femtosecond wideband pulse generation optical ring comprises a first light path switch, an amplifier, a wavelength division multiplexer, a narrowband fiber filter, a second light path switch and two phase modulators which are sequentially connected in series to form a loop, wherein the input end of the first light path receives a square signal; and the output end of the second light path switch outputs chirped pulses. The direct-phase-modulation-based femtosecond wideband pulse generation optical ring can endow generated wideband pulses with linear phases, suppress the production of nonlinear effects in the pulses and filter the light, with the central wavelength of 1,030nm, of the ytterbium-doped fiber amplifier to realize the high signal to noise ratio of a system, and better realizes secondary pulse phase modulation by controlling the external voltage of the phase modulators.

The invention provides an LED light source for medical endoscopes and a spectrum design method. The LED light source comprises a blue light source, a cyan light source, a green light source, a yellow light source, a red light source and a current controller. The LED light source is formed from the light sources with the colors. The blue light source consists of a blue light LED chip. The cyan light source, the green light source, the yellow light source and the red light source consist of blue light LED chips, the corresponding cyan fluorescent powder, green fluorescent powder, yellow fluorescent powder and red fluorescent powder, and filter films, wherein the filter films are blue light filer films. The spectrum design method comprises the steps of irradiating human body tissue and organ samples with the LED light source and a reference light source and obtaining a corresponding reflecting spectrum through testing; calculating color differences; adjusting the chips, the peak values of the fluorescent powder, and the currents of the various light sources according to the results to realize different spectrum distributions; performing repeated calculation until the color differences are consistent. The LED light source has the advantages of high light-emitting intensity, full spectrum without deficiency, flexible control and strong color restoration, has no ultraviolet and infrared parts and is biologically-friendly.

The invention provides a full-spectrum white-light micro-LED (light-emitting diode) chip, which relates to the technical field of high-quality illumination. The full-spectrum white-light micro-LED chip comprises a micro-LED array, a flaky fluorescent powder layer and a chip electrode. The micro-LED array comprises a substrate and a micro-LED chip arranged on the substrate; the flaky fluorescent powder layer comprises a fluorescent powder layer and silica gel, the fluorescent powder layer is consistent with the size of the micro-LED chip, the fluorescent powder layer is smeared onto the surfaceof the micro-LED chip, and two adjacent fluorescent powder layers are isolated by adopting silica gel; and the chip electrode is led out from the micro-LED chip, and the chip electrode is used as anelectric connection end of the micro-LED chip. The full-spectrum white-light micro-LED chip is small in light emitting area, simple in secondary light distribution design, controllable in color temperature and adjustable in spectrum.

The invention discloses red fluorescence powder for laser medical-treatment illumination and a preparation method and application thereof. The chemical formula of the red fluorescence powder is M1-x-zLixAl1-x-ySi1+x+yN3-yCy:zEu<2+> or M1-m+0.5n-pLimAl1-mSi1+mCnN3-n:pEu<2+>, wherein the x and the m are 0.01-0.3, the y and the n are 0.01-0.30, and the z and the p are 0.001-0.3. According to the preparation method of the red fluorescence powder for laser medical-treatment illumination, the fluorescence powder having good luminescence property is prepared by utilizing a high-temperature solid-state method and doping different atoms. In addition, the specific temperature is adopted for calcination, calcining reaction is performed at the temperature of 1500-1900 DEG C for 1-20 hours to enable components to be better bound together and to play excellent optical properties, and the red fluorescence powder is very suitable for manufacturing of medical-treatment illumination sources.

The invention discloses a nitride phosphor and a preparation method thereof. The nitride phosphor comprises the chemical composition of A1-xMpQqN3: xR, and the invention further discloses the preparation method of the nitride phosphor. The excitation spectrum of the phosphor adopts broadband excitation, the range covers almost ultraviolet and blue light, the phosphor is matched with LED chip emission spectrum and emits red light, the luminous efficiency is high, the half peak width is wide, and the chemical property is stable. The phosphor spectrum is adjustable, and the emission peak wavelength can be moved to 665 nm from 610 nm by changing the proportion of metallic elements in the A1-xMpQqN3: xR. High-purity ultrafine silicon powder can be further added to the phosphor so as to remove adsorbed oxygen contained in silicon nitride, the oxygen content of the phosphor is reduced, and the luminescence property of the phosphor is improved.

The invention discloses a single unit rotation type combined gas explosion sound source, and belongs to the technical field of naval mine resistance. The gas explosion sound source comprises a servo motor, a rotor, a stator shell, a piston and a piston cylinder; a cavity part of the rotor, which is provided with release holes, is inserted into the inside of the stator; both ends of the piston arerespectively positioned in the rotor and the piston cylinder; the piston cylinder is coaxially abutted with the stator shell; high-pressure gas inside the rotor is discharged and released by periodicopening and closing of the corresponding release holes on the rotor and a stator so as to generate a series of acoustic wave pulses oscillating on a wide band in water; by regulating displacement of the piston in the rotor, the number of opened ports of the rotor is controlled to regulate strength of the sound source; and the rotor is driven to rotate by the servo motor, when the opened release holes of the rotor are coincided with the release holes of the stator, a pulse with a specific frequency spectrum is generated, and the continuous change of the opened ports of the rotor in the continuous transmission process implements smooth control of the frequency spectrum. According to the invention, a physical field generated by a ship can be effectively simulated.

The invention discloses fluorescent materials with an aggregation-induced emission effect and circular polarization and a preparation method of the fluorescent materials. The general structural formula of the fluorescent materials is shown in the description, wherein R represents any one of H, phenyl, C1-C2 alkoxy substituted phenyl, C1-C3 alkyl substituted phenyl, trifluoromethyl substituted phenyl, thienyl, C1-C3 alkyl substituted thienyl and triphenylamine. After a ring-locking o-dinaphthol intermediate is synthesized from o-dinaphthol and 1,6-diiodohexane, a coupled product is synthesizedthrough a Suzuki coupling reaction, finally, an aldehyde group and malononitrile are subjected to a reaction, and the fluorescent materials are obtained. The fluorescent materials realize aggregation-induced emission characteristic and chirality in one molecular framework and can prevent quenching of circular dichroism spectrum, namely, the AACD effect, and by use of the two properties, microcrystals with different morphologies are obtained by self-assembly of the synthesized fluorescent materials, so that the compounds realize spectrum-adjustable circularly polarized light.

The invention provides fluorescent ceramic for warm white light illumination and a preparation method thereof. The chemical formula of the fluorescent material is Tb3 (1-x) Ce3xAl5 (1-2y) Mn5ySi5yO12,x is larger than or equal to 0.00005 and smaller than or equal to 0.15, y is larger than or equal to 0.00005 and smaller than or equal to 0.3, and the preparation method of the fluorescent ceramic comprises the steps that terbium oxide, aluminum oxide, cerium oxide, silicon dioxide and manganese dioxide are proportioned according to the chemical formula Tb3 (1-x) Ce3xAl5 (1-2y) Mn5ySi5yO12, powder prepared according to the stoichiometric ratio is mixed and then pressed and formed, a pressed green body is subjected to a phase change reaction through heat treatment to generate fluorescent ceramic of a terbium aluminum garnet phase, Ce < 3 + > ions and Mn < 2 + > ions enter a terbium aluminum garnet structure through diffusion under the high-temperature condition and replace existing Tb < 3+ > ions and Al < 3 + > ions respectively to form a light-emitting center; the Ce < 3 + > and Mn < 2 + > ion co-activated terbium aluminum garnet phase fluorescent ceramic for warm white light illumination is obtained. The fluorescent ceramic has wide-band yellow-green-orange-red fluorescence emission under blue light excitation, the fluorescence peak wavelength can be adjusted along with the concentration of doped Ce < 3 + > and Mn < 2 + >, and the fluorescent ceramic is suitable for warm white light illumination.

The invention discloses cerium-europium-terbium codoped nanocrystal fluorescent powder which has a chemical general formula of CexEunTb1-x-nF3 (x+n is greater than 0 and less than or equal to 1), wherein x represents a molar concentration of Ce3+, and n represents a molar concentration of Eu3+. A preparation method of the powder comprises the following steps: (1) weighing Ce(NO3)3.6H2O, Eu(NO3)3.6H2O and Tb(NO3)3.6H2O, adding [Bmim]NO3, stirring for 30-45min at 55-65 DEG C to prepare mixed liquid, (2) adding the mixed liquid into [Bmim]PF6, performing ultrasonic dispersion for 1-3h at 10-30Hz, and (3) cooling ultrasonic dispersion liquid to the room temperature, sucking liquid on a lower layer after liquid layering, washing with acetone, and then performing centrifugation and drying. The preparation method is simple, low in energy consumption and low in corrosion, and the prepared nanocrystal fluorescent powder has a good luminescent property.